This invention relates to endless tape cartridges and more particularly comprises a new and improved cartridge having an effective and inexpensive means for retaining the tape on the reel.
Endless tape cartridges are generally composed of a base, cover, reel and tape pack which comprise a small, easy to handle package. The endless tape is wound on the reel and is played out in the form of a loop from the inner convolution about guides at the front and returns to the reel at the outer convolution. In the prior art, a variety of different techniques have been employed to deal with excess tape in the loop which is played out of the pack due to mishandling of the cartridge. For example, in the prior art, special storage chambers have been designed in the cover and/or base to temporarily store excess tape in the loop so that it does not become jammed. One popular design calls for a storage chamber about the hub of the reel where the excess tape may collect. Another manner of dealing with this problem has been the provision of braking means in the cartridge which prevents rotation of the reel except when the cartridge is properly mounted on the player or recorder with which it is used.
All of the prior art arrangements have limitations. For example, those cartridges which provide a storage chamber about the hub of the reel for excess tape essentially encourage the inner convolutions of tape on the reel to ride up on the hub during use and to cone on the hub when the cartridge is inverted. The braking devices used to prevent rotation of the reel except when the cartridge is properly mounted on the player or recorder require special attachments in the recorders and players to release the braking device when in use. Unless such a system is universally adopted, cartridges with braking devices could not be used except on certain prescribed machines. Obviously, such a situation would not be tolerable.
Another technique for dealing with excess tape in the loop is the use of an annular wafer which is dropped on top of the tape pack on the reel about the hub. While these wafers perform satisfactorily, they require special threading of the tape through the center in the middle of the wafer, which adds significantly to the assemblying costs in manufacture.
Yet another technique for dealing with excessively long tape loops is the provision of a flange on the cover which extends downwardly on the side of the hub in very close proximity thereto. In order to work effectively, the flange must lie within a mil or two of the hub surface, which imposes very stringent manufacturing tolerances on all of the parts.
An important object of this invention is to provide a simple and inexpensive means for preventing inner convolutions of tape from riding up on the hub of the reel during use and from coning about the reel when the cartridge is inverted. A further object of this invention is to provide such a device which does not impose special assemblying techniques during manufacture. And another object of this invention is to provide such a device which does not require special cooperative features in the players and recorders with which the cartridge is used.
To accomplish these and other objects, the cartridge of this invention includes a flexible member which is carried by the cover and which automatically moves into place when the cover is assembled on the base. The member extends from beyond the periphery of the reel over the tape pack to a position where it engages the overhang of the top of the hub.
These and other objects and features of this invention will be better understood and appreciated from the following detailed description of several embodiments thereof, selected for purposes of illustration and shown in the accompanying drawing.